The Holographic Principle [1]}, [2]} has changed the way we look at quantum gravity and AdS/CFT [3]} is by far the most impressive of our present tools to attack this age-old problem of bringing quantum mechanics and gravity together. Although there has been spectacular progress in understanding Anti de Sitter spacetime and its dual field theories, particularly in the context of the original Maldacena correspondence between string theory on AdS\(_5 \times \)  S\(^5\)  and \(\mathcal {N}=4\)  Super Yang Mills theory in \(d=4\) , progress has surprisingly been much less impressive in non-AdS scenarios. The question of holography for asymptotically flat spacetimes, a subject that is clearly more relevant to the real world, especially for applications in say astrophysics and astrophysical black holes, has been receiving some attention more recently. Some of the earlier works include [4]}, [5]}, [6]}, [7]}. More recent attempts based on holography of the celestial sphere have built up following Strominger et al. These are somewhat tangential to our work here and we shall refer the reader to [8]} again for a more detailed exposition.
